Just six per cent of voters regard the EU as one of the most "important issues" facing Britain.

Former Conservative deputy chairman Lord Ashcroft warned the Tories that the more they talked about Europe the less likely they were to win the election. Photograph: Getty Images.

In his first conference speech as Conservative leader, David Cameron memorably told his party to stop "banging on[3]" about Europe. Lord Ashcroft, the former Conservative deputy chairman, billionaire party donor and prolific pollster[4], has just warned him to remember this injunction if he wants to win the next election (on which his hopes of a renegotiation, followed by a referendum, rest).

In an article[5] for ConservativeHome, the site he co-owns, Ashcroft writes:

The principal benefit of our referendum policy is not that it gives our campaign a headline; it is that it allows us to put the issue to rest and move the conversation on to what the voters want to discuss. Europe is important and we have a clear view about it. That does not mean we should allow it to top our agenda, or look as though it does. Few things would please Ed Miliband more.

Tories must remember that we can only get what we want once we win an election. The more we talk about changing our relationship with Europe, the less likely it is to happen.

As so often, Ashcroft's analysis is spot-on. While voters share the Tories' euroscepticism, they do not share their obsession with the subject. Polling[6] by Ipsos MORI (see above) regularly shows that fewer than 10 per cent of voters regard the EU as one of the most "important issues facing Britain". Its most recent survey[7] found that, even after the media attention devoted to the subject in recent months, just two per cent of voters regard the EU as "the most important issue" facing the UK today and just four per cent regard it as another "important issue".

Cameron knows and understands all of the above. One of the aims of his speech[8] was to settle the debate, calm his restive backbenchers and move on. Whether his MPs allow him to do so remains to be seen.